First off, sorry for such a long post. But I'm trying to include as much information to help you guys help me. (Also, I tend to get long-winded.)

So I've been having a battery drain problem all week. I finally tracked it down to the alternator was drawing current (3-4 amps) with the ignition off. When I disconnect the two-pin plug from the alt., there is zero current draw in the system.

It is wired as follows (I got the car this way). There is no ext. regulator.
Alternator terminal 1 is connected to the brown wire in the harness. This wire has 12V on it with the car and everything off.
Alternator terminal 2 is connected to the alternator output stud.

My question is this... is the brown wire supposed to "hot" all the time? I've looked at my Chevelle wiring diagram, but honestly can't figure out where this wire goes and if it is supposed to switch (with the ignition) at all.

Further, if it is supposed to be hot all the time, should the alternator be drawing any current when everything is shut off? I just installed the Powermaster alternator two months ago. Today I tried swapping the old Delco alternator in, and it too draws several amps with everything turned off.

If the brown wire is only supposed to be hot with the car on, perhaps I shorted it to something that is constantly on. But I can't figure out this wiring diagram. Where all does that brown wire go? According to my wiring diagram it looks like it goes through the bulkhead connector, the instrument cluster connector, and even the Fisher body connector back to the tail lighting.

Here's a few notes on the system:

Drain problem just started this week.
Last week, I replaced the column-mounted ignition switch. Thinking maybe I had a bad ignition switch, I tried disconnecting the switch from the harness, but still had the current draw.
Previous owner installed a Painless harness. He also installed a bastardized sheet metal instrument panel with aftermarket gauges. I subsequently installed an SS tach dash and spliced its harness to the Painless one (and everything has been working fine). That said, I don't expect the wiring to be 100% factory correct.


Thanks in advance. Hope you guys can help.

By the way, if you've read this far, maybe you're a glutton. I have another long-winded post in the "What's it worth?" section to which I haven't gotten my answer. Want more reading? Check it out...
What's it worth? (http://www.chevelles.com/forums/showthread.php?t=172396)

:beers:
Nelson V.

The brown wire should not have power with key off. Did you test the brown wire with it connected to the alternator, or did you disconnected it first. Did this problem start before or after the IGN switch replacement? Check other things that shouldn't have power with key off, like wipers, ignition, heater ect... If they have power, IGN switch is misadjusted. Did you do any recent wiring around the time the problem started? If so, look for a "backfeeding" issue. Backfeeding is where lets say the IGN circuit is getting power from a battery circuit after the IGN switch, usually caused by wiring something incorrectly.

The brown wire should not have power with key off. Did you test the brown wire with it connected to the alternator, or did you disconnected it first. Did this problem start before or after the IGN switch replacement? Check other things that shouldn't have power with key off, like wipers, ignition, heater ect... If they have power, IGN switch is misadjusted. Did you do any recent wiring around the time the problem started? If so, look for a "backfeeding" issue. Backfeeding is where lets say the IGN circuit is getting power from a battery circuit after the IGN switch, usually caused by wiring something incorrectly.

I tested the brown wire with the plug disconnected from the alternator. Still hot.
Problem started after I changed out the ignition switch. I have since tried disconnecting the ignition switch and unplugging the brown wire. Still hot.
As far as I can tell, nothing else that is supposed to be ignition-switched is hot with the ignition off.

Any idea where else that brown wires goes?

I tested the brown wire with the plug disconnected from the alternator. Still hot.
Problem started after I changed out the ignition switch. I have since tried disconnecting the ignition switch and unplugging the brown wire. Still hot.
As far as I can tell, nothing else that is supposed to be ignition-switched is hot with the ignition off.

Any idea where else that brown wires goes?
In a original idiot light car, the brown goes to the GEN lamp (which is the ground for the lamp) GEN lamp gets power from the IGN switch. There is also a bypass wire (should be brown wire w/white strip and is a resistor wire) incase the GEN lamp burns out, and goes to IGN switch. The brown and brown w/white strip tie together at firewall bulkhead connector.

In a original idiot light car, the brown goes to the GEN lamp (which is the ground for the lamp) GEN lamp gets power from the IGN switch. There is also a bypass wire (should be brown wire w/white strip and is a resistor wire) incase the GEN lamp burns out, and goes to IGN switch. The brown and brown w/white strip tie together at firewall bulkhead connector.

Thanks. I'll looks for those and see if I can make sense of my wiring. I must have somehow shorted the brown wire to 12V.